There are several approaches known in the art for using an infrared camera in order to track a pointing device like a light emitting pen for whiteboard purposes. These approaches offer a calibration after which the pointing device can be used for drawing on a whiteboard application. Only drag-and-drop actions are available in these applications, and a computer mouse can only be controlled in a two-dimensional space on the projected surface. Free movement of the corresponding mouse cursor without dragging as well as being able to stand away from the screen is not yet implemented in such approaches.
A potential usage of such a pointing is during remote presentations. The speaker cannot use a laser pointer for pointing, because it is not visible to the remote listeners. A mouse pointer can be used for pointing, but, requiring a computer mouse, it is quite uncomfortable for free speaking.
In the Patent Publication U.S. Pat. No. 7,683,881 B2 “VISUAL INPUT POINTING DEVICE FOR INTERACTIVE DISPLAY SYSTEM” by Sun et al. an interactive presentation system using a presentation computer, a computer controlled image projector and a projection screen is disclosed in which control of the presentation computer is accomplished by using a wireless optical pointer that projects an encoded control cursor onto the projection screen. The projected screen images are monitored by a video camera, and the control cursor is scanned, detected and decoded for emulation various keyboard commands and/or pointing device (mouse, touch pad, track ball) position-dependent cursor operations, e.g., select, move, left click, right click and double click. The control cursor is characterized by one or more primary attributes, for example image intensity or image repetition (blink) rate, that are independent of projection angle limitations as well the attributes of projected background images and objects. The control cursor is also characterized by one or more secondary attributes, for example pixel area (image size), colour, or pattern (image shape), that correspond with specific computer commands. Preferably, the image properties of the primary attributes and secondary attributes are mutually exclusive with respect to each other, respectively, thus allowing cursor-related processing operations to be performed conditionally and independently. The interactive image projection and display systems use technologies including ultrasonic, infrared and radio frequency (RF) techniques to provide increased user mobility relative to the computer processor and/or display screen. These technologies typically employ a transmitter and receiver to communicate control and status information between the operator and the computer.
In the Patent Publication U.S. Pat. No. 6,704,000 B2 “METHOD FOR REMOTE COMPUTER OPERATION VIA A WIRELESS OPTICAL DEVICE” by Carpenter, a method for remote operation of a computer having a cursor, via a wireless optical device is disclosed. The disclosed method comprises projecting a computer output display onto projection surface via a projecting means, generating an optical point on a desired cursor position on the projected image via the wireless optical device, capturing the image and optical point and transmitting this data to the computer, positioning the cursor on the projected image within a predefined distance of the position of the optical point, measuring a dwell time and executing a computer command when the dwell time exceeds predefined length of time. The executed computer commands may comprise any of a single left-mouse-click, double left-mouse-click, right-mouse-click, a mouse command, or a keyboard command.
State of the art embodiments are used to project an image on a projected surface and to recognize/interpret this pattern. Thereby, not the movement of the pointing device but the movement of the image on-screen is relevant.